Wednesday, February 29, 2012

Severe thunderstorms and tornadoes are hammering parts of Tennessee and Kentucky this afternoon, and it would be logical to assume those storms are heading our way.

They aren't, say meteorologists.

Instead, they say, we need to be looking to the southwest.

The severe weather in the Ohio and Tennessee valleys Tuesday afternoon eventually will move toward the North Carolina mountains but weaken. Meteorologist Pat Moore, of the National Weather Service office in Greer, S.C., said early Tuesday afternoon that some severe weather is possible, but those storms probably will lose their punch.

Instead, Moore says, the Charlotte area needs to be watching northeast Alabama and northwest Georgia.

The Storm Prediction Center in Norman, Okla., says there is a chance that a second area of severe weather could form this afternoon over Alabama and Georgia. If that were to happen, the storms would push across Atlanta and into the South Carolina upstate, eventually making a run at Charlotte in the early-morning hours.

Those are a lot of "if's."

Severe weather was forecast last Friday but didn't develop. Predicting the development of severe thunderstorms and tornadoes is a tricky business. Hence, our tricky forecast for tonight.

Moore's advice: "Monitor the forecast later tonight, especially before going to bed."

Friday, February 17, 2012

We're several days into the second half of February, which means the start of meteorological spring is less than two weeks away. The "official" start to spring is a little more than a month off.

And not a trace of snow has fallen this season at Charlotte/Douglas International Airport, the city's official reporting station.

That puts us in historic territory -- within sight of the first winter without even a trace of snow in the Queen City, in the 134 years that records have been kept.

If you're a snow-lover and are unhappy about what's happened this winter, here's some bad news. There isn't a definitive sign of frozen precipitation in the forecast for at least the next 10 days. And the outlook in March isn't good.

First, the important caveats.

We all know that snow can fall into April -- especially since all we're talking about here is a "trace." It wouldn't take much for a trace of snow to fall, perhaps at the end of a low pressure system, as the precipitation ends and colder air pours in. Frankly, that could happen Sunday afternoon or evening, as this weekend's big storm system moves up the East Coast.

March typically is among the snowiest months in Charlotte, although anything that falls usually melts very quickly.

But we've been locked in a persistent pattern this winter, with a variety of conditions that have conspired to keep the snow away.

La Nina has been one player, directing a series of mild air masses across the South. There hasn't been a blocking high pressure system over Greenland, or a persistent low pressure system in central or eastern Canada. Either of those conditions would steer arctic air into the East.

The latest bit of evidence pointing to a mild March is the Madden-Julian Oscillation (MJO). The MJO is a moving pattern in the atmosphere, and the latest forecast is that it will be in a phase across the United States in March that tends to produce mild weather.

The Climate Prediction Center, NOAA's long-range forecasting branch, is calling for above-average temperatures through at least March 2. And the longer-range forecast is for warmer-than-average weather through the entire spring and into early summer.

National Weather Service records in Charlotte show that at least a "trace" of snow has fallen every year since records started being kept in 1878-79. The most recent "trace" winter was 2005-06, when a trace was reported in three different months.

Like I said ... not even a whiff of snow so far this winter in the region.

The warm weather probably means a nightmare of crabgrass and weeds in our lawns; flea and tick populations that explode; and all kinds of other bad things this spring and summer. More about that at a later time.

Monday, February 13, 2012

In a mild winter like the one we're experiencing, even the mention of "snow" is a big deal.

Snow is falling in parts of the South today. More is expected tonight. But it won't happen in the Charlotte region.

There are several reasons, but the biggest is timing. A low pressure system which is causing the inclement weather across parts of the Mid-South today will not reach the Charlotte area until after daybreak Tuesday. By that time, temperatures are expected to be several degrees above freezing.

Anything that falls will fall as rain.

But it's the closest call so far this winter -- a winter which seems headed for a spot in the record books among the all-time mildest.

Before the weekend cold snap, Charlotte was on pace for one of the five mildest winters on record. In fact, it's been that way across nearly all the eastern half of the United States. There hasn't even been a trace of wintry precipitation in Charlotte.

A low pressure system is moving eastward out of Texas. Winter storm warnings are posted in parts of Arkansas, and a wide swath of the South -- from near Memphis, across northern Louisiana, northern Mississippi, northern Alabama, northwest Georgia, and parts of Tennessee -- are under winter weather advisories.

About an inch or two of snow and sleet are expected in that corridor later today.

In addition, a winter weather advisory has been posted by the local National Weather Service office (in Greer, S.C.) for parts of northeast Georgia and southwest North Carolina for tonight. An inch of snow and sleet is possible in that area, which includes Bryson City, Franklin and Sylva.

Rodney Hinson, of the Weather Service's office in Greer, said it's possible that a bit of sleet could fall briefly to the west of Charlotte -- we're talking about Shelby, Lincolnton and Morganton -- when the precipitation starts there around daybreak Tuesday.

But in Charlotte, temperatures are expected to be a couple degrees above freezing when the precipitation arrives.

Two other factors are working against the possibility of snow or sleet in Charlotte.

The strong high pressure system responsible for our cold weekend weather has pumped very, very dry air into the western Carolinas. It will take a long time Tuesday for precipitation to moisten the atmosphere and reach the ground. If the atmosphere weren't so dry, the precipitation would start earlier -- when temperatures were colder.

In addition, the storm system is forecast to weaken as it moves toward the Carolinas. Precipitation will be lighter when it reaches the Charlotte area.

And after Tuesday morning, a milder trend will take command for the rest of the week.

About this blog

Steve Lyttle says growing up in northeastern Ohio, with its foot-deep snows and summertime severe thunderstorms, fueled his interest in meteorology. He has written about weather for 10 years at The Observer. Join the discussion about weather trends and weird weather events -- whether local or around the world.